The shop workers’ union Usdaw said SSG – which is controlled by American brothers Mark and Philip Brewer – broke UK employment laws by trying to force staff to sign new contracts with longer hours, fewer holidays and poorer pension rights, and then sacking them last year.

Usdaw lodged claims with the employment tribunal for all 32 workers, who were based in Norwich, Cambridge, Lincoln, Sheffield, Worcester, Carlisle, Chester, Exeter, Newcastle and York.

Workers were then dismissed between February and June last year, many via e-mail from the US. Others heard the news from their colleagues, Usdaw said.

The exact payout, which includes wages owed when the workers were dismissed, is subject to a confidentiality clause.

Mark Brewer told the BBC he was unaware of the extent of the payout, and that details of the negotiations had not been disclosed to SSG.